Just 6 percent of Guangdong Province's urban land reserves remain undeveloped, which is insufficient to sustain healthy and consistent economic growth, a city planner has warned.

A recent survey by the Guangdong Urban & Rural Planning and Design Institute showed that 94 percent of the land available for urban construction in the province has already been developed, Wen Chunyang, the institute's vice-president, said.

The remaining reserves amount only to an area about the size of Guangzhou, the provincial capital, he said.

"With supply lagging far behind demand, some local governments have started exploiting farmland for urban construction projects. In the long term, this will have a detrimental impact on the province," Wen said.

Over the past 30 years, the province has attracted investors with the lure of low-cost and even free land. As a result, it is now home to tens of thousands of Hong Kong- and Taiwan-invested factories, he said.

Rather than continuing to pursue unlimited urban expansion, Wen wants governments in Guangdong to refresh their development strategies and consider introducing the idea of the "Compact City".

The Compact City, which is gaining increasing recognition as a sustainable form of development, is a high-density urban settlement whose characteristics include central area revitalization, mixed-use developments and key services and facilities such as hospitals, parks, schools and leisure areas, Wen said.

"With better-defined urban functions, increased density and improved public transport, Compact Cities can provide a better way of life for residents without further expansion of urban areas," he said.

The benefits of the Compact City include less dependency on private vehicles because of improved public transport - thus lowering emissions, a more efficient use of infrastructure and previously developed land, the preservation of green spaces, and the creation of a milieu for enhanced business activities. All of which adds up to a better quality of life, Wen said.

He added that governments should clearly define green spaces at the planning stage and ensure they are never lost to urban construction.